Since the membrane has a thickness of about \(4\times 10^{-9}\)  m [1]}, the RBC is considered as a 2D viscoelastic membrane filled with a Newtonian fluid: we adopt the Skalak model to describe the resistance to shear and area deformations [2]}, and the Helfrich formulation for the bending resistance [2]}. The viscous behaviour is described by the Standard Linear Solid (SLS) model, in which every element of the mesh can be thought of as characterised by a dashpot and an artificial spring connected in series that are connected together in parallel with another spring [4]}. For each node of the mesh, we compute the total force that is the sum of each of the above viscoelastic contributions.
